Selective system for party-line telephones.



No. 806,950. PATBNTED DEC. 12, 1905.

w. M. BRUCE, JR.

SELECTIVE SYSTEM FOR PARTY LINE TBLEPHONES. APPLICATION FILED APR.3.1905.

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UNITED STATES PATENT OFFICE.

WILLIAM M. BRUCE, JR, OF SPRINGFIELD, OHIO, ASSIGNOR OF ONE- THIRD TO JAMES S. BRAILEY, JR, OF WAUSEON, OHIO, AND ONE- THIRD TO CHARLES D. JUVENAL, OF SPRINGFIELD, OHIO.

SELECTIVE SYSTEM FOR PARTY-LINE TELEPHONES.

To all whom, it may concern.-

Be it known that I, WILLIAM M. BRUCE, J r.,

;a citizen of the United States, residing at magnets of the selector instruments.

My invention consists in the arrangements of magnets and circuits hereinafter described, and set forth in the claims.

The accompanying drawing is a diagram in a simple form of my circuit.

Like parts are represented by similar letters of reference.

In the said drawing, a and I) represent the opposite sides of an ordinary telephone-cir cuit, which may be extended to as many stations as is desired on the line, the circuit in one such station only being illustrated.

0 represents a magnet, which may be termed the main or operating magnet of the selector instrument, and having an armature c. d is a magnet also, which may be termed the auxiliary or releasing magnet, and has an armature d. The armature c ofthe operating-magnet c is adapted to make electrical contact at each operation with a contacting device 0 and the armature d of the auxiliary magnet (Z is adapted to normally make electrical contact with a contacting point (1 When the armature is operated by the magnetic force of the magnet (Z, it also makes electrical contact with a contacting point (i forming another electrical connection, the contact 01 at the same time being broken. This electrical contact d is preferably formed through the core of the magnet, this core for the purpose being insulated from the other parts of the magnet and connected to an electrical circuit hereinafter described.

-G represents the ground at a central or sig- Specification of Letters Patent.

Application filed April 3, 1905. Serial No. 258,700.

Patented Dec. 12, 1905.

nal station. G represents the ground at a substation or selector-station. A battery B at the central station has one pole connected to the ground and the other branched to switches or contacting devices, so that it may be connected to either or both sides of the main line a, b by the switches or contacting devices a and b.

' This form of circuit is intended to be used where a series of impulses are sent through an operating-magnet, the operation of which may be used to move a part of the mechanism to a position determined by the number of impulses, which when followed by the operation of another magnet releases the devices and permits them to'return to zero. In my improved form of circuits this is accomplished as follows: By. closing the switch I) the current is sent from one side of the grounded battery B through one side I) of the main line, then through the armature d of the magnet d, contacting devices (Z and o erating-magnet c, and thence to the groun G at the substation. This impulse causes the armature c to be attracted and make contact with the contacting device 0 which establishes a connection from the opposite side a of the line a through the magnet d. The switch a, however, being open, this magnet (i will not operate, and hence the magnet ,0 may be operated as many times as desired from the battery and one side of the line without affecting the magnet d, aXcept to close a circuit through the same from the other side of the line, making it possible to operate the same under certain conditions. If the switch a be closed without the switch I), the same side of the battery B would be connected to the opposite side aof the line; but with the switch I) open the circuit through the magnet (i would be broken, because of the armature c of the unenergized magnet 0 being away from the con tact 0 If both switches should be closed, however, thus throwing one side of the bat tery B onto both sides a and I) of the main line, the current would flow from the battery B through both sides of the line and would' operate the magnet c, which in turn would close the circuit at c and permit a current to pass from the line a through the magnet d to ground. As soon as the magnet 11 is energized the armature 01 would be attracted and break the current through the magnet c, allowing the armature c to drop, which would in turn break the connection at 0 The circuit which passes from the contacting devices 0 through the auxiliary magnet 11 to ground is branched, as shown at d, to the contact (1 Hence when the armature d is attracted a new circuit is established from the side I) of the line through armature d, the contact-point d branch (1, through the magnet d to ground, which circuit will allow the magnet d to continue to be energized so long as the switch 1) remains closed after the closing of both switches. It will be seen that in the operation of these operating and auxiliary magnets by the use of one side of the line of the battery with grounded connections the two line-wires are never used in circuit; but the two wires are tied together when both switches are operated; but both sides of the line are used as one line from a single pole of the battery to ground, thus insuring the operating of the main and auxiliary magnets in any position which they may occupy and Without interfering with the currents which maybe passing through both sides of the lines a b for the purpose of talking or otherwise. The use of both sides of the line, however, is only for the purpose of moving into opera tive position the auxiliary or releasing magnet d, and by using both sides of the main line with the grounded connection this is effectively accomplished and in a way that cannot be interfered with at any substation by shortcircuiting the line, which might be the case when one side only of the line is used. As soon as the magnet d has been energized a new circuit is established by which the current passes through one side of the line only, so that the full strength of the current is obtaingd-in the operation of the auxiliary magnet It will be understood that any number of these stations having a main and auxiliary V magnets may be employed, connected, as

shown, to the respective sides of the lines a b, operated from the circuit-closing devices a 6 each of the instruments being operated exactly alike when the circuit-closing devices are operated.

Having thus described my invention, I claim- 1. Ina system for selective signals, a main circuit, a source of electrical supply, one pole of which is grounded and the other pole adapted to be connected to either or both sides of said main circuit, a grounded connection from one side of said main circuit, including a circuit-breaker and a main operating-magnet, and a grounded connection from the other side of said main circuit including a circuit-breaker and an auxiliary magnet, the circuit-breakers in each of said circuits being adapted to be controlled by the magnet in the other circuit, and means for sending an impulse from said source of electrical supply in the same direction through either or both sides of said circuit, substantially as and for the purpose specified.

2. In combination with a telephone-circuit, an operating-magnet in a grounded circuit connected to one side of said main circuit, an auxiliary magnet in a grounded circuit normally disconnected from the other side of said main circuit, but adapted to be brought into connection therewith by the operation of the main magnet, a circuit-breaker operated by said auxiliary magnet to break the .adapted to be controlled by the magnet in the other branch line, and an auxiliary circuit adapted, when the auxiliary magnet is operated, to change the connection of the auxiliary magnet from one side of the main line to the other side, substantially as and for the purpose specified.

4. The combination witha main telephoneline ofan operating-magnet and a releasingmagnet located in grounded branch lines, in cluding circuit-breakers, which branch lines are connected to opposite sides of said main telephone-line, said releasingmagnet being adapted to be brought into circuit by the operating-magnet, and when operated to cut out said operating-magnet, and an auxiliary circuit through the core of said releasingmagnet adapted to establish an electrical connection with the opposite side of the main telephone-line when the armature of said releasing-magnet is operated, substantially as and for the purpose specified.

In testimony whereof I have hereunto set my hand this 14th day of March, A. D. 1905.

WILLIAM M. BRUCE, JR.

Witnesses:

F. LLEWELLYN WALKER, (bus. I. WELCH. 

